A collection of memorabilia from the Beat era in the back of a San Francisco bookstore.

Its buzzing collection honors vibrator history.

There is no trying to fall in love with this Star Wars fountain, you just do or do not.

A 140-year-old castle with underground caves hidden in San Francisco.

An artsy hidden staircase leads to breathtaking views of San Francisco.

A psychedelic labyrinth on the San Francisco bay.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

In the middle of a suburban Denver neighborhood is a cave that once provided solace for a prominent Ute chief and his family.

A mental health hospital dating back more than 139 years, now features a museum.

This Boeing KC-97 tanker is now a restaurant for aviation lovers.

Final resting place of a 19th century gold prospector and convicted cannibal.

A lively annual event in which thousands of people race to push coffins heavy with bodies up a hill.

A stark reminder of the huge nuclear weapons plant that once stood on the site and its effect on the surrounding area.

A collection of fading fantasy tchotchkes lines this dirt road in the Colorado wilderness.

When zealous marijuana enthusiasts kept stealing the "Mile 420" highway marker, the State of Colorado got creative.

The childhood home of Henry Jones Jr. is now an adventure-themed bed and breakfast.

Rather than a run-of-the-mill franchise hotel, this lodging has been decked out in dinosaur decor.

Abandoned silver mine strewn with wrecked and twisted structures.

An architect in Aspen used psychedelics as his muse while building this mushroom masterpiece.

The largest self-built castle in the U.S., six decades in the making.

A small horde of mythical creatures lurk almost imperceptibly within the museum's wildlife dioramas.

These old stone ruins in the Oregon wilderness were once bathrooms and are steeped in legends of murder.

Meet the bronze beloved pet to a family of famous peeing statues.

An 80-year-old plane tree is devouring an iron bench at Ireland's oldest law school.